Optical device and imaging unit provided with optical device

Abstract

The present disclosure provides an optical device with which it is possible to achieve size reduction and reduce manufacturing costs, and an imaging unit provided with the optical device. An optical device (10) comprises: an outermost layer lens (1) (light-transmitting body) that transmits light of a predetermined wavelength; a housing (2) that holds the outermost layer lens (1); a vibrating body (3) that is in contact with the outermost layer lens (1) held by the housing (2); and a piezoelectric element (5) that is provided on the vibrating body (3) and vibrates the vibrating body (3). The vibrating body (3) is a cylindrical body, and is shaped to have a plurality of groove portions (30) in a support portion (33) (third part) connecting a connecting portion (31) (first part) that is in contact with the outermost layer lens (1) and a vibrating portion (32) (second part) on which the piezoelectric element (5) is provided.

Description

Optical device and imaging unit including optical device

[0001] The present disclosure relates to an optical device and an imaging unit including the optical device.

[0002] Imaging units are installed at the front or rear of a vehicle, and images obtained by the imaging units are used to control vehicle safety devices and perform driving assistance control.Since such imaging units are often installed outside the vehicle, raindrops (water droplets), mud, dust, and other foreign matter can adhere to the transparent bodies (protective covers and lenses) that cover the exterior.

[0003] If foreign matter adheres to the light-transmitting body, the foreign matter will be reflected in the image obtained by the imaging unit, making it difficult to obtain a clear image. Therefore, in Japanese Patent No. 6819844 (Patent Document 1), a vibration device that vibrates the light-transmitting body in order to remove foreign matter adhered to the surface of the light-transmitting body is provided in the imaging unit.

[0004] Patent No. 6819844

[0005] The imaging unit described in Patent Document 1 uses a vibration device including a light-transmitting body, a first cylindrical body, a spring portion, a second cylindrical body, and a vibration body to vibrate the light-transmitting body and remove foreign matter adhering to the surface of the light-transmitting body. However, in the imaging unit described in Patent Document 1, the vibration device that vibrates the light-transmitting body has a three-dimensional spring structure in which the first cylindrical body is provided on top of the second cylindrical body via a spring portion, which makes it prone to becoming large in size, and the shape is complex, making processing time-consuming and increasing manufacturing costs.

[0006] Therefore, an object of the present disclosure is to provide an optical device that can be miniaturized and whose manufacturing costs can be reduced, and an imaging unit that includes the optical device.

[0007] According to an embodiment of the present disclosure, there is provided an optical device including a light-transmitting body that transmits light of a predetermined wavelength, a housing that holds the light-transmitting body, a vibrating body that is in contact with the light-transmitting body held by the housing, and a piezoelectric element that is provided on the vibrating body and vibrates the vibrating body. The vibrating body is a cylindrical body having a shape that has a plurality of grooves in a third portion that connects a first portion that contacts the light-transmitting body and a second portion that has the piezoelectric element provided thereon.

[0008] An imaging unit according to one embodiment of the present disclosure includes the optical device described above and an imaging element arranged so that the light-transmitting body is in the field of view.

[0009] According to the present disclosure, the vibrating body is a cylindrical body having a shape with a plurality of grooves in a third part connecting a first part that contacts the translucent body and a second part that has a piezoelectric element provided therein, so that the optical device and the imaging unit that includes the optical device can be made smaller, and manufacturing costs can be reduced.

[0010] 1 is a schematic diagram of an imaging unit according to embodiment 1. FIG. 2 is a cross-sectional view of the imaging unit according to embodiment 1. FIG. 3 is a schematic diagram of a vibrating body according to embodiment 1. FIG. 4 is a diagram for explaining deformation when the vibrating body according to embodiment 1 is vibrated. FIG. 5 is a diagram for explaining sound pressure distribution when the vibrating body according to embodiment 1 is vibrated. FIG. 6 is a diagram for explaining heat distribution when the vibrating body according to embodiment 1 is vibrated. FIG. 7 is a schematic diagram of a modified example of the vibrating body according to embodiment 1. FIG. 8 is a schematic diagram of another modified example of the vibrating body according to embodiment 1. FIG. 9 is a schematic diagram of a vibrating body according to embodiment 2. FIG. 10 is a graph showing a stress comparison between the vibrating body according to embodiment 1 and the vibrating body according to embodiment 2. FIG. 11 is a schematic diagram of a vibrating body according to modified example 1. FIG. 12 is a schematic diagram of a vibrating body according to modified example 2. FIG. 13 is a schematic diagram of a vibrating body according to modified example 3.

[0011] An optical device according to an embodiment and an imaging unit including the optical device will be described in detail below with reference to the drawings. Note that the same reference numerals in the drawings indicate the same or corresponding parts. The optical device described below is applied to, for example, an in-vehicle imaging unit, and can vibrate a transparent body (e.g., the outermost lens) to remove foreign matter adhering to the surface of the transparent body. The optical device is not limited to applications in in-vehicle imaging units. For example, the optical device can also be applied to security surveillance cameras, imaging units for drones, and the like.

[0012] (Embodiment 1) Fig. 1 is a schematic diagram of an imaging unit 100 according to embodiment 1. Fig. 2 is a cross-sectional view of the imaging unit 100 according to embodiment 1. Note that the X, Y, and Z directions in the figure indicate the horizontal, depth, and height directions of the imaging unit 100, respectively. The imaging unit 100 includes an optical device 10 and an imaging device 20. The optical device 10 has an outermost lens 1, a housing 2, a vibrating body 3, an inner lens 4, and a piezoelectric element 5. The imaging device 20 has an imaging element 6, a circuit board 7, and a case 8.

[0013] After adjusting the alignment between the outermost lens 1 and the inner lens 4, the optical device 10 is combined with an imaging device 20 including an imaging element 6 to form the imaging unit 100. In this embodiment, the optical device 10 is described as having an inner lens 4, but the inner lens 4 may also be provided on the imaging device 20 side. Furthermore, the imaging unit 100 only needs to have at least the optical device 10 and the imaging element 6 arranged so that the outermost lens 1 and the inner lens 4 are in the field of view.

[0014] The imaging element 6 is an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor) sensor, and is mounted on a circuit board 7. The circuit board 7 may be mounted with semiconductor elements such as a general-purpose IC (Integrated Circuit) or ASIC (Application Specific Integrated Circuit) that control the imaging element 6, as well as with semiconductor elements that generate signals for driving the piezoelectric element 5. The circuit board 7 is fixed to the case 8 at a position where the alignment of the outermost lens 1 and inner lens 4 with the imaging element 6 has been adjusted.

[0015] The outermost lens 1 is a translucent body that transmits light of a predetermined wavelength (e.g., a wavelength of visible light or a wavelength that can be captured by an imaging element), and is, for example, a convex meniscus lens. Note that the optical device 10 may use a transparent member such as a protective cover instead of the outermost lens 1. The protective cover may be made of glass or a resin such as transparent plastic.

[0016] An end of the outermost lens 1 is held by an end of a leaf spring 2a extending from the housing 2. An adhesive is filled between the outermost lens 1 and a retainer 2b, which is the end of the leaf spring 2a. Furthermore, the optical device 10 has a vibrating body 3 provided at a position in contact with the outermost lens 1 to vibrate the outermost lens 1 held in the housing 2.

[0017] FIG. 3 is a schematic diagram of a vibrating body 3 according to embodiment 1. FIG. 3(a) is a perspective view of the vibrating body 3, and FIG. 3(b) is a side view of the vibrating body 3. As shown in FIG. 3(a), the vibrating body 3 is a cylindrical body. As shown in FIG. 3(b), the vibrating body 3 is composed of a connecting portion 31 (first portion) that contacts the outermost lens 1, a vibrating portion 32 (second portion) that has a piezoelectric element 5, and a supporting portion 33 (third portion) that connects the connecting portion 31 and the vibrating portion 32. The connecting portion 31, the vibrating portion 32, and the supporting portion 33 may be formed integrally or separately.

[0018] The connecting portion 31 is a portion that comes into contact with the outermost lens 1, and has a cylindrical shape that is stretched in the axial direction (Z direction) of the cylindrical body. The vibrating portion 32 is a portion that vibrates together with the vibration of the piezoelectric element 5, and has a flange portion in the radial direction of the vibrating body 3 to make it easier to install the piezoelectric element 5. The supporting portion 33 is a side portion of the vibrating body 3, and has multiple grooves 30 in the shape of a horizontal Y (tuning fork) formed in a row at equal intervals in the circumferential direction of the vibrating body 3. The grooves 30 penetrate the supporting portion 33 and are openings that penetrate the vibrating body 3 in the radial direction.

[0019] Groove 30 has a horizontal Y-shape (tuning fork shape) and is symmetrical about the radial axis of vibrating body 3. Groove 30 is formed so that one end contacts connecting portion 31 and the other end contacts vibrating portion 32. The remaining portion of support portion 33 due to the provision of groove 30 becomes a plurality of U-shaped pillars 35 that connect connecting portion 31 and vibrating portion 32. These pillars 35 function as springs that vibrate outermost lens 1 in the Z direction.

[0020] Pillar 35 has a horizontal U-shape. As shown in Fig. 3(b) , pillar 35 has a shape in which the connection portion with connecting portion 31 and the connection portion with vibrating portion 32 are arranged in a substantially straight line. Therefore, the vibration of piezoelectric element 5 causes the U-shaped portion of pillar 35 to narrow or widen, thereby vibrating outermost lens 1 in the Z direction.

[0021] 4A and 4B are diagrams illustrating deformation that occurs when the vibrating body 3 according to the first embodiment is vibrated. In Fig. 4A, the vibration of the piezoelectric element 5 narrows the U-shaped portion of the pillar 35, causing the outermost lens 1 to deform downward in the figure (negative side in the Z direction). In Fig. 4B, the vibration of the piezoelectric element 5 widens the U-shaped portion of the pillar 35, causing the outermost lens 1 to deform upward in the figure (positive side in the Z direction). The vibrating body 3 alternately vibrates the entire outermost lens 1 in the Z direction and removes foreign matter adhering to the surface of the outermost lens 1 by repeating the deformation shown in Fig. 4A and the deformation shown in Fig. 4B.

[0022] The piezoelectric element 5 is provided on the surface of the vibrating section 32 opposite to the side in contact with the outermost lens 1. The piezoelectric element 5 has a hollow circular shape and vibrates by being polarized in the thickness direction, for example. The piezoelectric element 5 is made of lead zirconate titanate piezoelectric ceramics. However, (K,Na)NbO ３ Other piezoelectric ceramics such as LiTaO may also be used. ３ A piezoelectric single crystal such as

[0023] The hollow circular piezoelectric element 5 vibrates in the radial direction, and this vibration is converted into vibration in the Z direction (up and down in the figure) by the support part 33 of the vibrating body 3, causing the outermost lens 1 to vibrate in the Z direction. As can be seen from Figure 4, the vibrating body 3 displaces the outermost lens 1 in the Z direction by the multiple pillars 35 of the support part 33 elastically deforming like a spring. Note that the vibration of the vibrating body 3 also causes elastic deformation of the leaf spring 2a of the housing 2 that holds the outermost lens 1.

[0024] In the optical device 10, by processing the grooves 30 on the Z-direction side surface (support portion 33) of the vibrating body 3, it is possible to form a spring (pillar 35) that expands and contracts in the Z direction. Therefore, the optical device 10 can be made smaller in volume and more compact than an optical device that uses a two-dimensional leaf spring extending in the X and Y directions to vibrate the outermost lens. Furthermore, the optical device 10 can be made less expensive because the vibrating body 3 is a simple cylindrical body that can be formed simply by processing the grooves 30 on its side surface.

[0025] The vibrating body 3 is, for example, a cylindrical body made of SUS420J2 with a diameter of 15 mm, with eight grooves 30 machined into the side surface (support portion 33) to form eight U-shaped pillars 35. A piezoelectric element 5 with an outer diameter of 19 mm (inner diameter of 13 mm) and a thickness of 1.0 mm is provided on the bottom surface (vibration portion 32) of the vibrating body 3. The top surface (connection portion 31) of the vibrating body 3 contacts the outermost lens 1 made of glass with a diameter of 14.4 mm and a thickness of 3.5 mm. A simulation was performed on an optical device 10 having the vibrating body 3, in which a voltage Vp-p of 20 Vp-p was input to the piezoelectric element 5 to vibrate the outermost lens 1. The results showed that the resonant frequency was 26.6 kHz, the resonant resistance was 302.6 Ω, and the maximum displacement was 9.8 μm, achieving the required vibration performance. The voltage Vpp input to the piezoelectric element 5 is not limited to 20 Vpp, but may be, for example, about 40 Vpp to 60 Vpp, in which case the maximum displacement will be 20.0 μm or more. Here, the voltage Vpp is the voltage difference (peak-to-peak value) between the maximum value (+Vpp) and the minimum value (-Vpp) of the drive signal (AC signal).

[0026] The product size of the optical device 10 can be significantly reduced compared to an optical device having a configuration (comparison configuration) including a first cylindrical body, a spring portion, and a second cylindrical body, and can be reduced in size in the radial direction by approximately 33%. Since the product size of the imaging unit 100 depends on the radial size of the optical device 10, adopting the configuration of the optical device 10 can reduce the product size of the imaging unit 100. The volume of the cylindrical body of the vibrating body 3 is approximately half the volume of the comparison vibrating body.

[0027] In the comparative vibrating body, the first and second cylindrical bodies are configured to house lenses, image sensors, and other components, which enclose the surroundings. This prevents the air compressed by the vibration of the light-transmitting body from escaping, which could damp the vibration of the light-transmitting body. Furthermore, the heat generated by the image sensors and other components cannot be released to the outside, which means that heat tends to build up inside the first and second cylindrical bodies.

[0028] On the other hand, in the optical device 10, a groove 30 is provided on the side surface (support portion 33) in the Z direction of the vibrating body 3, and the inside and outside of the cylindrical vibrating body 3 are connected via the groove 30 (opening). Therefore, in the optical device 10, air compressed by the vibration of the light-transmitting body can be released to the outside, and damping of the vibration of the outermost lens 1 can be reduced.

[0029] The air compressed by vibration can be measured by sound pressure. FIG. 5 is a diagram illustrating the sound pressure distribution when the vibrating body 3 according to embodiment 1 is vibrated. In the comparative vibrating body, vibrating the first cylindrical body and the light-transmitting body in the Z direction compresses the air between the light-transmitting body and the inner lens, increasing the sound pressure. High sound pressure in this area damps the vibration of the light-transmitting body. However, in the optical device 10, even when the outermost lens 1 is vibrated in the Z direction, the air between the outermost lens 1 and the inner lens 4 can escape through the groove 30 on the side surface (support portion 33) of the vibrating body 3, thereby reducing the sound pressure in this area, as shown in FIG. 5. In other words, the sound pressure between the outermost lens 1 and the inner lens 4 does not increase, thereby reducing the damping of the vibration of the outermost lens 1. Note that in FIG. 5, the intensity of the sound pressure is indicated by the shade of the hatching, with darker hatching indicating areas with higher sound pressure, such as the outside of the outermost lens 1.

[0030] FIG. 6 is a diagram illustrating the heat distribution when the vibrating body 3 according to the first embodiment is vibrated. FIG. 6 illustrates the results of a simulation of the heat distribution when 1 W of power is applied to the imaging element 6. The results shown in FIG. 6 illustrate the temperature distribution of the optical device 10 after a predetermined period (e.g., 1,000 seconds) has elapsed since the imaging element 6 was activated, so that the heat generated by the imaging element 6 reaches a thermal equilibrium state. As shown in FIG. 6 , the optical device 10 has a heat dissipation effect that can suppress the temperature rise inside the cylindrical vibrating body 3 by dissipating the heat generated by the imaging element 6 through the groove 30. In FIG. 6 , the shade of the hatching indicates the temperature, with the darker hatching indicating the higher temperature, and the temperature being higher near the imaging element 6.

[0031] As described in FIG. 3 , the vibrating body 3 has eight grooves 30 machined on its side surface (support portion 33) to form eight U-shaped pillars 35. However, the vibrating body 3 is not limited to this configuration, and the grooves 30, each shaped like a horizontal Y, may be enlarged in the circumferential direction. FIG. 7 is a schematic diagram of a modified example of the vibrating body 3 according to the first embodiment. In the vibrating body 3A, as shown in FIG. 7 , four grooves 30A enlarged in the circumferential direction are machined on its side surface (support portion 33), to form four U-shaped pillars 35. That is, in the vibrating body 3A, grooves 30A larger in volume than the grooves 30 are provided on the side surface (support portion 33) of the vibrating body 3. Note that, although the thickness of the pillars 35 in the vibrating body 3A is the same as that of the pillars 35 in the vibrating body 3, the thicknesses may be different. In addition, in the vibrating bodies 3 and 3A, the plurality of grooves 30 and 30A are provided at equal intervals in the circumferential direction of the side surface (support portion 33), but they may be provided at different intervals. Furthermore, in the vibrating bodies 3 and 3A, the shape of the pillars 35 is not limited to a U-shape, and they may be a shape in which horizontal U-shaped pillars are stacked in the Z direction.

[0032] As described in FIG. 3 , the groove 30 is an opening that penetrates the support portion 33 and penetrates the vibrating body 3 in the radial direction. However, the groove 30 is not limited to an opening, and may be a recess that does not penetrate the support portion 33. FIG. 8 is a schematic diagram of another modified example of the vibrating body 3 according to the first embodiment. In the vibrating body 3B, as shown in FIG. 8 , a plurality of horizontal Y-shaped grooves 30B are formed in a row at equal intervals in the circumferential direction of the vibrating body 3B. The grooves 30B do not penetrate the support portion 33, but are recesses having bottom surfaces 36 in the radial direction of the vibrating body 3B. In other words, the vibrating body 3B has a structure in which a plurality of pillars 35 are connected at the bottom surfaces 36. The position of the bottom surface 36 is not limited to the interior side of the vibrating body 3B, and may be provided on the exterior side of the vibrating body 3B. Furthermore, one or more through holes may be provided in the bottom surface 36 of the groove 30B.

[0033] (Embodiment 2) The vibrating body 3 according to embodiment 1 has been described as having a plurality of U-shaped pillars 35 connecting the connecting portion 31 and the vibrating portion 32, as shown in Fig. 3. In embodiment 2, a vibrating body having pillars other than a U-shape will be described. Fig. 9 is a schematic diagram of a vibrating body 3C according to embodiment 2. Note that the optical device 10 having the vibrating body 3C and the imaging unit 100 including the optical device 10 have the same configuration as described in embodiment 1, and therefore the same configuration will be described with the same reference numerals assigned to the same components, and detailed description will not be repeated.

[0034] Fig. 9(a) is a perspective view of vibrating body 3C, and Fig. 9(b) is a side view of vibrating body 3C. As shown in Fig. 9(a), vibrating body 3C is a cylindrical body. As shown in Fig. 9(b), vibrating body 3 is composed of a connecting portion 31 (first portion) that contacts outermost lens 1, a vibrating portion 32 (second portion) that has piezoelectric element 5 provided thereon, and a supporting portion 33 (third portion) that connects connecting portion 31 and vibrating portion 32.

[0035] A plurality of step-shaped grooves 30C are formed in the support portion 33 at equal intervals in the circumferential direction of the vibrating body 3C. The grooves 30C penetrate the support portion 33 and are openings that penetrate the vibrating body 3C in the radial direction.

[0036] Groove 30C has a stepped shape and is point-symmetric. Groove 30C is formed so that one end contacts connecting portion 31 and the other end contacts vibrating portion 32. The remaining portion of support portion 33 due to the provision of groove 30C forms a plurality of cantilever-shaped pillars 35C connecting connecting portion 31 and vibrating portion 32. These pillars 35C function as springs that vibrate outermost lens 1 in the Z direction. Groove 30C is not limited to an opening, but may be a recess that does not penetrate support portion 33.

[0037] By making the pillars 35C cantilever-shaped, it is possible to reduce the stress applied to the pillars 35C when the outermost lens 1 is vibrated. Therefore, by making the pillars 35C cantilever-shaped, the reliability of the vibrating body 3C is improved in terms of mechanical strength. Fig. 10 is a graph showing a comparison of stress between the vibrating body 3 according to embodiment 1 and the vibrating body 3C according to embodiment 2. Fig. 10 shows the results of a comparison of the stress generated per unit displacement between the vibrating body 3 having a U-shaped pillar 35 and the vibrating body 3C having a cantilever-shaped pillar 35C.

[0038] 10, the vibrator 3C with cantilevered pillars 35C reduces the maximum and minimum principal stresses to about half of those of the vibrator 3 with U-shaped pillars 35. Note that even if pillars 35C are made meander-shaped by increasing the folded-back portion instead of cantilevered, the maximum and minimum principal stresses can be reduced in a similar manner.

[0039] (Modifications) In the optical device 10 according to the first embodiment, it has been described that a plurality of grooves 30 each having a horizontal Y-shape are formed on the side surface of the vibrating body 3, and in the optical device 10 according to the second embodiment, it has been described that a plurality of step-shaped grooves 30C are formed on the side surface of the vibrating body 3C. However, the shape of the grooves formed on the side surface of the vibrating body is not limited to a horizontal Y-shape or a step-shape. Below, modifications of the shape of the grooves formed on the side surface of the vibrating body are described.

[0040] (1) FIG. 11 is a schematic diagram of a vibrating body according to Modification 1. FIG. 11(a) shows a vibrating body 3D having a plurality of rectangular parallelepiped grooves 30D formed on its side surface. As shown in FIG. 11(a), the grooves 30D are rectangular parallelepiped, and are symmetrical about a line and a point with respect to the radial direction of the vibrating body 3. The remaining portions of the support portion 33 due to the provision of the grooves 30D become a plurality of pillars 35D connecting the connection portion 31 and the vibrating portion 32. These pillars 35D function as springs that vibrate the outermost lens 1 in the Z direction. Note that the grooves 30D are not limited to openings, and may be recesses that do not penetrate the support portion 33.

[0041] 11(b) shows a vibrating body 3E having a plurality of grooves 30E formed on its side surface, each groove having a complex shape that combines a U-shape with a cantilever beam shape. The grooves 30E are formed so that one end contacts the connecting portion 31 and the other end contacts the vibrating portion 32. The portions of the support portion 33 that are left by providing the grooves 30E form a plurality of pillars 35E that connect the connecting portion 31 and the vibrating portion 32. These pillars 35E function as springs that vibrate the outermost lens 1 in the Z direction. The grooves 30E are not limited to openings, but may be recesses that do not penetrate the support portion 33.

[0042] The optical device 10 having the vibrating bodies 3D and 3E and the imaging unit 100 including the optical device 10 have the same configuration as described in embodiment 1, so the same components will be denoted by the same symbols and detailed descriptions will not be repeated.

[0043] (2) FIG. 12 is a schematic diagram of a vibrating body according to Modification 2. FIG. 12(a) illustrates a vibrating body 3F having a plurality of slit-shaped grooves 30F formed on its side surface. As shown in FIG. 12(a), the grooves 30F are slit-shaped and point-symmetric. The grooves 30F are formed so that one end contacts the connecting portion 31 and the other end contacts the vibrating portion 32. The remaining portion of the support portion 33 due to the provision of the grooves 30F becomes a plurality of pillars 35F connecting the connecting portion 31 and the vibrating portion 32. These pillars 35F function as springs that vibrate the outermost lens 1 in the Z direction. Note that the grooves 30F are not limited to openings, but may be recesses that do not penetrate the support portion 33.

[0044] FIG. 12(b) shows a vibrating body 3G having a plurality of wave-shaped grooves 30G formed on its side surface. As shown in FIG. 12(b), the grooves 30G are wave-shaped and point-symmetric. The grooves 30G are formed so that one end contacts the connecting portion 31 and the other end contacts the vibrating portion 32. The remaining portion of the support portion 33 due to the provision of the grooves 30G becomes a plurality of pillars 35G connecting the connecting portion 31 and the vibrating portion 32. These pillars 35G function as springs that vibrate the outermost lens 1 in the Z direction. Note that the grooves 30G are not limited to openings, but may be recesses that do not penetrate the support portion 33.

[0045] The optical device 10 having the vibrating bodies 3F and 3G and the imaging unit 100 including the optical device 10 have the same configuration as described in embodiment 1, so the same components will be denoted by the same symbols and detailed descriptions will not be repeated.

[0046] (3) FIG. 13 is a schematic diagram of a vibrating body according to Modification 3. FIG. 13 illustrates a vibrating body 3H having a plurality of S-shaped grooves 30H formed on its side surface. As shown in FIG. 13, the grooves 30H are S-shaped and point-symmetric. The grooves 30H are formed so that one end contacts the connecting portion 31 and the other end contacts the vibrating portion 32. The remaining portion of the support portion 33 due to the provision of the grooves 30H forms a plurality of pillars 35H connecting the connecting portion 31 and the vibrating portion 32. These pillars 35H function as springs that vibrate the outermost lens 1 in the Z direction. The grooves 30H are not limited to openings, but may be recesses that do not penetrate the support portion 33. The optical device 10 having the vibrating body 3H and the imaging unit 100 including the optical device 10 have the same configuration as those described in Embodiment 1. Therefore, the same components will be denoted by the same reference numerals and detailed description will not be repeated.

[0047] (Other Modifications) The imaging unit according to the above-described embodiment may include a camera, LiDAR, radar, etc. Furthermore, a plurality of imaging units may be arranged side by side.

[0048] The imaging unit according to the above-described embodiment is not limited to an imaging unit installed in a vehicle, but can be similarly applied to any imaging unit that includes an optical device and an imaging element arranged so that a light-transmitting body is in the field of view, and that requires removal of foreign matter from the light-transmitting body.

[0049] (Aspects) (1) An optical device according to the present disclosure includes a light-transmitting body that transmits light of a predetermined wavelength; a housing that holds the light-transmitting body; a vibrating body that contacts the light-transmitting body held in the housing; and a piezoelectric element that is provided on the vibrating body and vibrates the vibrating body, wherein the vibrating body is a cylindrical body and has a shape that has a plurality of grooves in a third part that connects a first part that contacts the light-transmitting body and a second part that has the piezoelectric element.

[0050] As a result, the optical device according to the present disclosure can be made smaller and manufacturing costs can be reduced because the vibrating body is a cylindrical body having a shape with multiple grooves in the third part connecting the first part that contacts the translucent body and the second part in which the piezoelectric element is provided.

[0051] (2) In the optical device described in (1), each of the plurality of grooves has a shape that is line-symmetrical with respect to an axis that is the radial direction of the vibrating body.

[0052] (3) In the optical device according to (1) or (2), the plurality of grooves are formed so that one end thereof contacts the first portion and the other end thereof contacts the second portion.

[0053] (4) In the optical device according to any one of (1) to (3), the third portion provided with the plurality of grooves has a plurality of U-shaped pillars connecting the first portion and the second portion.

[0054] (5) In the optical device according to any one of (1) to (4), the plurality of grooves are provided at equal intervals in the circumferential direction.

[0055] (6) In the optical device according to any one of (1) to (3), each of the plurality of grooves has a shape that is symmetrical with respect to a point.

[0056] (7) In the optical device described in (1), the third portion provided with the plurality of grooves has a plurality of cantilever-shaped or meander-shaped pillars connecting the first portion and the second portion.

[0057] (8) In the optical device according to any one of (1) to (7), the plurality of grooves are openings that penetrate the cylindrical body in the radial direction.

[0058] (9) In the optical device according to any one of (1) to (8), the vibrating body has the first portion, the second portion, and the third portion integrally formed.

[0059] (10) An imaging unit according to the present disclosure includes the optical device according to any one of (1) to (9) and an imaging element arranged so that the light-transmitting body is in the field of view.

[0060] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0061] 1 Outermost lens, 2 Housing, 3, 3A to 3H Vibrating body, 4 Inner lens, 5 Piezoelectric element, 6 Imaging element, 7 Circuit board, 8 Case, 10 Optical device, 20 Imaging device, 30, 30A to 30H Groove portion, 31 Connection portion, 32 Vibrating portion, 33 Support portion, 35, 35C to 35H Pillar, 36 Bottom surface, 100 Imaging unit.

Claims

1. A light-transmitting body that transmits light of a predetermined wavelength; A housing for holding the light-transmitting body; a vibrator in contact with the light-transmitting body held by the housing; a piezoelectric element provided on the vibrating body to vibrate the vibrating body, The optical device, wherein the vibrating body is a cylindrical body having a shape having a plurality of grooves in a third portion connecting a first portion in contact with the translucent body and a second portion in which the piezoelectric element is provided.

2. The optical device according to claim 1 , wherein each of the plurality of grooves has a shape that is line-symmetrical with respect to an axis extending in a radial direction of the vibrating body.

3. 3. The optical device according to claim 1, wherein one end of each of the plurality of grooves is in contact with the first portion and the other end is in contact with the second portion.

4. 3. The optical device according to claim 1, wherein the third portion having the plurality of grooves includes a plurality of U-shaped pillars connecting the first portion and the second portion.

5. The optical device according to claim 1 , wherein the plurality of grooves are provided at equal intervals in a circumferential direction.

6. The optical device according to claim 1 , wherein each of the plurality of grooves has a shape that is point symmetric.

7. The optical device according to claim 1 , wherein the third portion having the plurality of grooves includes a plurality of cantilever-shaped or meander-shaped posts connecting the first portion and the second portion.

8. The optical device according to claim 1 , wherein the plurality of grooves are openings that penetrate the cylindrical body in a radial direction.

9. 3. The optical device according to claim 1, wherein the first portion, the second portion, and the third portion of the vibrating body are integrally formed.

10. The optical device according to claim 1 or 2; an imaging element disposed so that the light-transmitting body is in a field of view;